Electric welding apparatus



NOV. 7, 1944. w BAIRD 2,361,918

ELECTRIC WELDING APPARATUS Filed Dec. 18, 1942 5 Sheets-Sheet l INVENTOR 1 ALBERT W. BAlR ATTORNEY Nov. 7, 1944. A. w. BAIRD ELECTRIC WELDING APPARATUS Filed Dec. 18, 1942 3 Sheets-Sheet 2 '//////////////////////l/l/l/l/l/f/////// Wr/l/I/ ATTORNEY NOV. 7, 1944. w, BAIRD 2,361,918

ELECTRIC WELDING APPARATUS Filed Dec. 18, 1942 3 Sheets-Sheet 3 INVENTOR ALBERT W. BAIRD BY i ATTORNEY Patented Nov. 7, 1944 'U'NITEWD' STATES PATENT OFFICE Albert W. Baird, Crani'ord, N. 1., assignor to The Linde Air Products Company, a corporation of Ohio Application December 18, 1942, Serial No. 469,395

Claims.

- in powdered or granular form, and an electric thecomposition. The fusing tip of the electrode,- which is covered by the welding composition, is

, maintained at the proper distance from the work welding current .is passed from an electrode or welding wire to the work through the welding composition into which the fusing end of the electrode is inserted. During the welding operation, as the electrode is fed to the work and simultaneously translated along the seam through the welding composition, part of the latter is locally fused at successive portions of the seam, and molten metal of the electrode is deposited in the seam and coalesced with the fused edges of the seam to provide a uniformly strong weld. An excess of unfused welding composition is maintained as a blanket over the welding zone.

This method has heretofore been practiced principally by machines using welding heads which feed the electrode automatically as the welding progresses. In all such machines there is relative translatory movement between the work and the welding head. The excellent quality of welds produced by this method of welding, as wellas other considerations, makes it desirable that the process be made available for use in applications in which installation of automatic welding machinery would be inconvenient or impractical. Portable equipment has been developed whichmay be used in some of such applications; but even this equipment does not completely satisfy the demand which exists'ior broadening the field of use of this method of welding.

In particular, portable or hand welding equipment hitherto used has not been capable of handling the relatively large diameter welding rods and relatively heavy welding currents essential to the efficient use of the Jones et al. electric welding process.

In Patent No. 2,275,910, issued March 10, 1942, in the name of Harry E. Kennedy, there is disclosed a manual electric welding method, using portable or hand welding equipment, in which the welding com tion of the above Jones et al. patent is heaped n the work and the fusing end of an electrode or welding rod is inserted into by holding the electrode at an acute angle to the work and observing the welding voltage as indicated by suitable means such as a voltmeter. The voltage is maintained substantially constant by varying either the pressure with which the electrode is forced into the welding composition or the angle at which the electrode is directed toward the work. This latter is accomplished by pivoting the electrode about the unfused welding composition as a fulcrum.

It is among the objects of this invention toprovide a portable or manually operated welding electrode feeding mechanism which is adapted to handle large sizes of welding electrodes; to provide such a mechanism with which the distance between the end of the welding electrode and the work may be easily maintained at a substantially uniform value; to provide such a mechanism including improved means for conducting relatively large electric welding currents to the welding electrode as it is advanced through the mechanism toward the work to be welded; to provide such a mechanism including means for readily indicating to the operator the distance between the fusing end of the welding electrode and the work; to provide such a mechanism in which all the necessary controls are suitably grouped at a position convenient of access to the operator; to provide such a mechanism including a novel electrode feeding clutch means for advancing the electrode toward the work; to provide such a mechanism which is readily adjustable in length and usable with various sizes of electric welding electrodes; and to provide such a mechanism which is simple in construction, economical to manufacture, and eflicient in operation.

These and other objects of the invention will in part be obvious and in part become apparent from the following description and accompanying drawings, in which:

Fig. 1 is-an elevation view of the portable welding apparatus of the present invention in opera tive relation with the work to be welded;

Figs. 2 and 2a, when aligned longitudinally, are a plan view of the apparatus shown in Fig. 1;

Fig. 3 is an elevation view of a bus bar assembly forming part of the present invention;

Fig. 4 is a perspective view of a welding nozzle or contact jaw forming part of the bus bar assembly of Fig. 3; Y

Fig. 5 is a longitudinal view, partly in section,

taken on the line 8-5 of Fig. 2 and looking in the direction of the arrows;

Fig. 5a is a longitudinal view, partly in section,

v taken on the line lit-la of Fig. 2a and looking in the direction of the arrows;

Fig. 6 is a transverse sectional view taken on the line 6-. of Fig. 5a and looking in the direction of the arrows;

Figs. 7, 8 and 9 are, respectively, a cut-away view, a front view and a rear view of an element of a welding rod feeding mechanism forming part of the present invention;

Figs. 10 and 11 are perspective views ofa roller aligning block and a roller, respectively, adapted to be used with the element illustrated in Figs. 7, 8 and 9;

Fig. 12 is a-longitudinal sectional view illustrating part of a modified form of portable welding apparatus embodying the principles of the present invention;

F18 13 is a transverse sectional view taken on theline l3-l2.oi Fig. 12 and looking-in the direction of the arrows; and

Figs. 14, 15 and'16 are perspective views of sub-assemblies of the welding apparatus of the present invention.

Generally speaking, the welding apparatus of the present invention comprises an elongated handle assembly to the forward end of which is secured a bus bar assembly for conducting electric current to a welding rod or electrode mounted in the handle assembly. A reciprocable rod feeding means, slidably mounted in the handle assembly, upon movement in one direction, is adapted to grip the welding rod and advance it end of a sleeve 8 of insulating material, and the bus bar assembly B is secured to the other end of sleeve S. At its forward end, handle H is formed toward the work, and, upon movement in the reverse direction, to release the welding rod. A welding rod nozzle or contact Jaw, forming part of the bus bar assembly, grips the welding rod upon reverse movement of the feeding means to prevent reverse movement of the rod. A remote control switch for the welding current is conveniently mounted upon the handle assembly adjacent an operating means for the welding and feeding means. In order that the operator may maintain the welding voltage, and hence the distance between the fusing end of-the electrode and the work tobe welded, a' voltmeter is mounted on the handle assembly in such a position that its indications are readily visible to the operator during a welding operation.

Referring more particularly to Figs, 1 throughv 11 of the drawings, the embodiment of the invention therein illustrated comprises an elongated handle assembly A on the forward end of which ismounted a bus bar assembly B including a bus bar B and a contact iaw'ornczzle J. An insulating guard plate P is mounted on the assembly B and extends outwardly therebeyond. A welding rod or electrode E is advanced toward the work W to be welded by means of a feeding means 1'' slidabiy mounted in handle assembly A and reciprocated longitudinally of. assembly A by an operating means 0. On movement of feeding means I" in one direction, rod E is advanced toward the work. and, on movement of feeding means F in the opposite direction, rod E is restrained against movement by contact iaw J, all as more fully described hereinafter. A remote control switch C for the welding current is mounted adjacent operating means 0 and a voltmeter V-is mounted 8:1 gandle assembly A adiacentbus bar assem- The handle assembly A includes a generally tubular, elongated metal handle I! secured to one ---portion, and intermediate its ends the Jaw is with a split clamp portion 24 adapted to detachably receive a reduced tubular extension 2| formed. on a bushing 22 secured by screws 22 in the rear end of sleeve 8. Intermediate its ends, handle I! is formed with perpendicularly related offset housings 24 and 25. Housing 24 has an opening closed by a removable cover plate 21 on which is mounted control switch C. Conductors 24 are brought into housing 24 through an entrance bushing 29. and are connected at one end to switch C and-at the other end to a welding current master switch (not shown). A gear segment 30, secured in a recess II in an operating handle 32, is mounted in housing 2! on a pin 33, and forms part of the feeding means operating means 0. At its rear end, handle H is formed with an enlarged and threaded recess 24 in which is inserted an annular plate "and a felt washer I! both held in position by an entrance bushing 21 of insulating material threadedly mounted in recess 24. Entrance bushing I1 is formed with an outwardly flared opening II to receive welding rod E. r

A bushing 4| is secured by screws 4| in the forward end of sleeve 8 and is formed with a split clamp portion 42 and a voltmeter housing 44. The split clamp portion 42 detachably receives the intermediate portion of an elongated tube 44 of insulating material, formed with a flaring opening 44 at its rearward end and a reduced section 46 at its forward end. A groove 41 is formed in tube 44 and extends from a point adjacent reduced section 44 to a recess 4!, and receives a conductor 4| connected at one end to a metal clamp 50 and at the other end to a terminal Si in recess 48. a

The voltmeter V is retained in housing 43 by a split retaining ring 82, and oneterminal it of the voltmeter is connected by conductor 54 to terminal II. The other terminal I of the voltmeter receives a conductor I4, brought into housing 43 through entrance bushing II, and adapted to be connected at its opposite end (not shown) to the. work W to be welded. voltmeter housing 43 is properly positioned on tube 44 by a pin l4 engaging a bolt 59 in the clamp portion 42 of bushing 44.

The bus bar assembly B is secured to the reduced section 4| of tube 44, and comprises bus bar B, insulating guard plate 1 and contact law or nozzle J. Bus bar 3' comprises a central cylindrical portion 4|, split clamps II and 42, and a cable terminal block 43, on the forward clamp it, formed to receive welding current cables 04. The rear end of split clamp I2 is reduced in diameter at II to fit beneath and have electrical contact with clamp ll. splitvclamp l2 detachably secures the bus bavassembly to tube 44.

Guard plate P is secured by bolts CI to the forward face of terminal block 43 and extends outwardly beyond the terminal block 08 and split clamp Oi, which latter detachably secures bus bar B tocontactiaworncaaleJ.

Nozzle or law J is a generally tubular member.

of copper or some other suitable electrically conductive material. The forward end 44 of the nozzle is turned down to form a frusto-conical formed with a circumferential recess II receiving a clamp 10. A plurality of slots II, preferably four in number, extend longitudinally of noazle J from the forward end thereof to points rearwardly of recess 88, where each slot terminates in a circular aperture 12. The described construction provides the forward end of the jaw or nozzle with flexible gripping fingers 18, for a purpose to be described.

The feeding means or mechanism F is slidably mounted in the sleeve 8, and is moved in one direction by operating means and in' the other by a spring 15. As the feeding mechanism is in elec trical contact with the welding rod, an insulating plate 16 is disposed between the rear end of the feeding mechanism and bushing 22.

Mechanism F comprises asleeve 11 fitting closely in sleeve S, apertured end plates 18 and" 18, and a cylindrical block 88, all united by suitable fastening means into a single cartridge or unit. Block 88 is formed with an axial bore or passage 8| at least larger in'diameter than the largest size of electrode to be handled by the apparatus. At its rear end, bore 8| is intersectedby rearwardly converging bores or passages" and 88, which preferably are substantially rectangular in cross section. Bores 82 and 83 receive springs :3 form aunitbyrivets III. 'Iheteethofspurgear I81 mesh with the teeth III on rack I".

A pin 8 is mounted on roller bearings I in the apertured ears 85, and an operatinghandle 82' is secured to the pin and extends forwardly tube I88 forwardly; spring moving the tube tion is as follows.

84, roller aligning blocks 85 and rollers 88."

Blocks 85 are Q-shaped and have a cross section similar to that of bores or passages 82 and 88. Each block includes a pin 81 to receive one of the springs 84 which also abut end plate 18. For a purpose to be described hereinafter, springs 84 normally urge blocks 85 and rollers 88 rearwardly and inwardly toward bore 8| which receives electrode or rod E.

In the embodiment of the invention shown in Figs. 1 through 6, the operating means 0 for the feeding mechanismincludes a tube 88 slidably mounted in handle H and provided with rack teeth 88 which mesh with gear segment 38. Handle H is formed with an inner shoulder 88 which acts as a guide for the rear end of tube 88 and the forward end of the tube 88 is guided in bushing 22, where it abuts the rear end of a tube ill. The forward end of tube 8| is tapered and has a wedge fit in insulating plate 16. I When operating handle 32 is pivoted toward handle H to its dotted line position in Fig. 5a, gear segment 38 moves the tubes 88 and 8| and rod feeding mechanism F forwardly. Upon release of operating handle 32, spring 15 moves the feeding mechanism F and tubes 88 and 8| rearwardly, causing handle 32 to pivot outwardly to its full line position in Fig. 5a.

An alternative form of operating means or mechanism 0' is illustrated in Figs. 12 and 13. In this form, the handle H is formed with an oflset housing 83 having an opening 94. and with spaced apertured cars 85. An internal shoulder 86 is formed in handle H, and a bushing 91 abuts this shoulder and is held in place by a second bushing 98 having a reduced forward end extending into bushing 81. Bushing 88 is retained in position by a set screw 88. A tube I88, having a forward section I8I larger in diameter than its rearward section I 82, has mounted thereon a rack I83 which abuts the shoulder formed by the junction of sections IM and I82 and is held in place by a split ring I8| seated in a groove in section I82. A collar I85 seated on the latter section abuts the forward end of the reduced section of bushing 81 to limit the rearward movement of' tube I88. The section I82 of tube I88 slides in bushing 88.

A pin I88 extends between the side walls of housing 83, and spur gears I81 and I88 are mounted thereon on roller bearings I88. A washer II8 separates large gear I81 from small gear I88 and the gears and washer are united to I88 rearwardly upon release of handle 82'.

The operation of the apparatus oLthe inven- The rod or electrode E is inserted in the entrance bushing 81 of handle H or in tube I88 in handle'I-I', and is pushed through the apparatus until its forward end projects beyond contact jaw J. Clamp 18 on jaw J is tightened so that the flexible fingers 18 exert a gripping action on the'electrode E. Conductor 56 is secured to the work by a suitable I clamp so that, when switch C or C is actuated to initiate the flow of welding current, voltmeter V will indicate the welding voltage.

When the operating means 0 or 0' are actuated to move the feeding means F forwardly, the rollers 86 move rearwardly along passages 82 and 83 and inwardly toward electrode E under the influence of springs 84. Thereby, the rollers 86 grip the electrode E and the latter moves forwardly with the feeding mechanism. when the handles -32 or 32' are released, the spring 18 moves the feeding mechanism F rearwardly. The rollers 88 now move forwardly along passages 82 and 83' and outwardly away [from the electrode. This is due to the gripping action of fingers 13 of jaw J which restrain rearward movement of rod E. Consequently, rollers rollalong rod E in such a direction that the move relatively forwardly and outwardy along passages 82 and 83 and do not exert a gripping action on the rod E. Hence, mechanism F acts as a one-way clutch and jaw J with its flexible fingers 18 con-' stitutes means to restrain reverse movement of electrode or rod E.

In Fig. l, the apparatus is illustrated in position to weld according to the method described and claimed in Kennedy Patent No. 2,275,810. A quantity of a granular fusible mineral welding material G isheaped on the work W to be welded and the fusing end of electrode E is submerged beneath the materal. The rod or electrode E is directed toward the work at an acute angle. As the axis of voltmeter V makes asubstantially complementary acute angle with the axis of the electrode, the :face of voltmeter V is substantially parallel to the work. Thus, the voltmeter indications, are readily visible to the operator of the welding apparatus.

During the welding operation, the welding current melts and coalesces metal from the electrode and from the work and progressively fuses 'a portion of the welding material G. As described inthe Kennedy patent, the fusing end of ting movement of the apparatus. By observing the reading of voltmeter V, the welding voltage and hence the distance between the fusing end of rod E and the work can be maintained substantially constant. As the rod melts, the operating means or 0' may be actuated to cause mechanism F to advance the rod or electrode toward the work. By suitable manipulation of the pressure of the rod against material G, or preferably by suitable control of the pivoting of the rod about material G as a fulcrum, and by careful manipulation of operating means 0 and 0', all in accordance with the indications of voltmeter V, an accurate control of the welding voltage, and hence of the distance between the end of rod E and work W, may be easily maintained.

While the apparatus of the present invention is primarily a rod feeding mechanism, portions of the apparatus, as shown in Figs. 14, 15 and 16, may be detached and used as electrode holders. Thus, Fig. 14 illustrates an electrode holding unit comprising voltmeter V, bus bar assembly B and tube 44. In Fig. 15, a longer tube 44' is illustrated. Both these units including the voltmeter V are well adapted to practice the method of Kennedy Patent No. 2,275,910, even though no feeding of the electrode relative to the holder is possible. Additionally, the longer tube 44' may .be substituted for the tube 44 in the apparatus of Figs. 1 through 13 if it is desired t increase the overall length or the apparatus.

Fig. 16 illustrates how the larger tube 44' may be detached. and used as a simple electrode holder. Obviously, the shorter tube 44 may be used alone in a similar manner. In all forms of the invention, relatively large diameter rods and relatively large welding currents may be efilcientl handled.

While specific embodiments of the principles of the invention have been illustrated and described, it will be readily appreciated by those skilled in the art that the invention may be otherwise embodied within the scope of the principles thereof.

What is claimed is:

1. Welding rod feeding apparatus comprising, in combination, a tubular handle; a sleeve secured to said handle; a bus bar assembly secured to said sleeve; 8. member reciprocably mounted in said handle and adapted to receive a welding rod; a welding rod feeding mechanism slidably mounted in said sleeve and operatively associated with said member; manually operable means mounted on said handle and engaging said mem- P ber, said means being operative to move said member and-said mechanism in one direction; resilient means mounted in said sleeve and opwork to be welded, and, upon movement in the opposite direction, being adapted to move freely along said welding rod; and means restrainin movement of said welding rod upon movement of said mechanism and said member in said opposite direction.

2. Welding rod feeding apparatus as claimed in claim 1, in which the last named means comprises a flexible current carrying contact jaw forming part of said bus bar assembly.

3. Welding apparatus as claimed in claim 1, in which said member comprises a tube formed with rack teeth and said means for moving said member and mechanism in one direction comprises a gear segment pivotally mounted on said housing and operatively associated with said rack teeth, and a handle for operating said gear segment.

4. Welding apparatus as claimed in claim 1, including a rack secured to said member; a first gear pivotally mounted on said housing and engaging said rack; a second gear secured tosaid first gear; a gear segment engaging said second gear; and means for rotating said gear segment to operate said gears to move said member in said one direction.

erative to move said mechanism and said member in the opposite direction; said mechanism,

5. Electric welding apparatus comprising, in combination, an elongated tubular member formed with a threaded recess and an inner shoulder at one end, and a split clamp at the other end; ametallic bushing having a reduced extension fitting in the split clamp 01 said elongatedtubular member; an apertured ielt washer 'in said threaded recess; an entrance bushing securing said felt washer in said threaded recess; a sleeve of insulating material secured to said metallic bushing; a voltmeter housing formed with a bushing secured in the opposite end of said sleeve, said housing being formed with a split clamp; a first tube formed with rack teeth and slidably engaging the inner shoulder in said elon gated tubular member and said metallic bushing; a second tube slidably disposed in said metallic bushing and engaging said first tube; a welding rod feeding mechanism slidably mounted in said sleeve and operatively associated with said sec ond tube; an elongated tubular insulating member secured in the split clamp of said voltmeter housing; a bus bar assembly formed with a split clamp engaging said elongated tubular insulating member; a welding current carrying contact nozzle secured in the opposite endof said bus bar assembly; a plate of insulating material secured to said bus bar assembly and extending radially therebeyond; gear means having teeth meshing with said rack teeth, mounted on said elongated tubular member for moving said tubes and feeding mechanism in one direction; and resilient means urging said welding rod feeding mechanism and said tubes in a direction opposite to the direction in which the same are moved by said gear means.

'- ALBERT W. BAIRD. 

